A 34-year-old Adams County man is charged with first-degree murder after allegedly running over a pedestrian following a fight on the side of the road in Thornton, according to an arrest affidavit.

Mathew Nick Lopez was arrested July 23 after Thornton police tracked a red Ford SUV seen leaving the scene of a fatal hit-and-run around 1:30 a.m. that day.

Officers responded to a hit-and-run crash on the 84th Avenue bridge over Interstate 25 and found a man injured on the ground, police wrote in an arrest affidavit.

The man, identified as 48-year-old Ruben Vasquez, was taken to the hospital and later died.

A witness told police Vasquez was standing on the bridge alone yelling and mumbling when Lopez pulled up next to him, got out of the vehicle and the men started yelling at each other.

Lopez and Vasquez then started fighting, and the witness told police Vasquez was swinging a large chain with a lock on it toward Lopez.

Lopez then got back into the SUV and sped toward Vasquez, hitting him and dragging him before speeding off, the witness told police.

Investigators tracked the vehicle and Lopez to a relative’s house in Wheat Ridge, where they found the SUV and detained Lopez, according to the affidavit.

Lopez told police he had stopped to see if Vasquez needed help when Vasquez attacked him with the lock and chain and hit him over the head, causing a head injury so “he could not think straight.”

Lopez later told police he saw Vasquez fall but was not sure he hit him and was scared and “kind of blacked out,” then fled the scene without calling police.

Lopez is in custody on a $75,000 bail and is set to appear in court Sept. 26.

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Originally Published: August 14, 2024 at 2:09 p.m.